Fluid heating device

ABSTRACT

A fluid heating device for heating chemicals mainly containing sulfuric acid, which is capable of suppressing reduction of heating efficiency even if a fluid mainly containing sulfuric acid is heated, includes a translucent inner tube composed of quartz or the like, a lamp heater disposed in the inner tube, a translucent outer tube disposed outside the inner tube, which is composed of quartz or the like, translucent side plates disposed on both sides of the outer tube, which include quartz or the like, and an amorphous carbon pipe disposed between the outer tube and the inner tube, which functions as a light-absorbing material, wherein the amorphous carbon pipe is disposed so as to be brought into contact with chemicals passing through a space between the outer tube and the inner tube.

TECHNICAL FIELD

The present invention relates to a fluid heating device, and the like,and particularly to a fluid heating device capable of suppressing thereduction of a heating efficiency even if a sulfuric acid-based fluid isheated.

BACKGROUND ART

In an RCA washing step in which semiconductor wafers are washed, foreignsubstances attached to a semiconductor wafer are removed by usingchemicals. In the RCA washing step, the chemicals to be used variesdepending on the treatment. For example, when particles attached to asemiconductor wafer are removed, an ammonium hydroxide/hydrogen peroxidemixture is used; whereas when metal ions attached to a semiconductorwafer are removed, a hydrochloric acid/hydrogen peroxide mixture isused. When the semiconductor wafers are washed with the chemicals suchas the ammonium hydroxide/hydrogen peroxide mixture or hydrochloricacid/hydrogen peroxide mixture, it is necessary to raise the temperatureof the chemicals used for washing to, for example, approximately 80° C.

Conventionally, for controlling the temperature of the chemicals, thechemicals are heated by using a fluid heating device, thereby raisingthe temperature of the chemicals. The fluid heating device heats thechemicals by using, for example, a lamp heater such as a halogen lampand by bringing a quartz glass tube into contact with the chemicalswhile electric current is applied to the lamp heater that has been putinto the quartz glass tube, thereby heating the solution (see, forexample, Patent Document 1).

When the lamp heater (the halogen lamp) is used as a heat source and theintended chemicals described above are treated in the fluid heatingdevice, radiation (emission) performs 90% or more of heating. Inaddition, because the radiation heating can have a very high heatingcapacity per unit area, it is possible to make the device smaller.

PRIOR ART TECHNICAL DOCUMENT Patent Document 1

[Patent Document 1] Japanese Patent No. 3847469 (paragraphs 0019 to0029)

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

However, when the fluid to be heated is sulfuric acid or is a sulfuricacid-based fluid, it has properties such that the rate of absorption ofthe near-infrared rays emitted from a halogen lamp is low (60 to 70% ina case of sulfuric acid). For that reason, when the sulfuric acid-basedchemicals are heated by using a conventional fluid heating device, 30%to 40% of light energy that is transmitted through a quartz glass tubeand the chemicals are directly absorbed into a heat-insulating material,which is provided outside the chemicals, and much of the heat energythereof is released outward; as a result, a temperature of a case of thefluid heating device is raised or the temperature of the solution maynot reach a desired temperature. In other words, there is a problem inwhich the heating efficiency of the fluid heating device is reduced.

The present invention has been made in consideration of the situationsdescribed above, and the object of the present invention is to provide afluid heating device capable of suppressing reduction of a heatingefficiency even if a fluid mainly containing sulfuric acid is heated.

Means for Solving the Problem

In order to solve the problem described above, a fluid heating deviceaccording to one aspect of the present invent ion is a fluid heatingdevice for heating chemicals mainly containing sulfuric acid, includinga translucent inner tube; a lamp heater disposed in the inner tube; atranslucent outer tube disposed outside the inner tube; a translucentside plates disposed on both sides of the outer tube; and alight-absorbing material disposed between the outer tube and the innertube, wherein the light-absorbing material is disposed so as to bebrought into contact with chemicals passing through a space between theouter tube and the inner tube.

According to the fluid heating device described above, when thelight-absorbing material is disposed between the inner tube and theouter tube convection-heating and conduction-heating can be promoted.More particularly, even if a fluid mainly containing sulfuric acid isheated, reduction of a heating efficiency can be suppressed, because thelight energy is absorbed in the light-absorbing material and isconverted into heat energy, and the conduction-heating heats thechemicals.

Also, in a fluid heating device according to one aspect of the presentinvention, it is possible that the inner tube, the outer tube and theside plates are each made of quartz, and the inner tube and the outertube are each connected to the side plates by welding to integrallyform. This enables the risk of leakage of the chemicals to be reduced.

Also, in a fluid heating device according to one aspect of the presentinvention, it is preferable that the light-absorbing material forms apassage for the chemicals passing through a space between the outer tubeand the inner tube.

Effect of the Invention

According to the present invention, a fluid heating device capable ofsuppressing reduction of a heating efficiency can be provided, even if afluid mainly containing sulfuric acid is heated.

BRIEF DESCRIPTION OF THE DRAWINGS

[FIG. 1](a) is a schematic view showing a longitudinal section of afluid heating device according to a first embodiment of the presentinvention; and (b) is a cross-sectional view corresponding to A-A′ linein (a).

[FIG. 2] A schematic view showing a longitudinal section of a fluidheating device according to a second embodiment.

[FIG. 3](a) is a schematic view showing a longitudinal section of afluid heating device according to a third embodiment of the presentinvention; and (b) is a cross-sectional view corresponding to B-B′ linein FIG. 3( a).

[FIG. 4](a) is a schematic view showing a longitudinal section of afluid heating device according to a fourth embodiment of the presentinvention; and (b) is a cross-sectional view corresponding to D-D′ linein FIG. 4( a).

[FIG. 5] A schematic view showing a cross section of a fluid heatingdevice according to a fifth embodiment of the present invention.

[FIG. 6] A schematic view showing a cross section of a fluid heatingdevice according to a sixth embodiment of the present invention.

[FIG. 7] A schematic view showing a cross section of a fluid heatingdevice according to a seventh embodiment of the present invention.

[FIG. 8] A schematic view showing a cross section of a fluid heatingdevice according to an eighth embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring to Figures, a first embodiment of the present invention willbe explained below.

FIG. 1 shows schematic views showing a fluid heating device according toa first embodiment of the present invention, in which FIG. 1( b) is across-sectional view corresponding to A-A′ line in FIG. 1( a), and FIG.1( a) is a longitudinal cross-sectional view corresponding to a-a′ linein FIG. 1( b). This fluid heating device is a device for controlling atemperature of sulfuric acid-based chemicals such as sulfuric acid, amixed solution of sulfuric acid and aqueous hydrogen peroxide, or amixed acid of sulfuric acid and nitric acid by heating it. The phrase“sulfuric acid-based chemicals” herein refers to chemicals containing50% or more of sulfuric acid.

The structure of the fluid heating device will be explained below.

As shown in FIGS. 1( a) and (b), the fluid heating device has an innertube 3 a composed of a cylindrical container, and a lamp heater 4 suchas a cylindrical halogen lamp whose diameter is smaller than that of theinner tube 3 a is coaxially inserted into the inside of the inner tube,as a heat source. In addition, the outside of the inner tube 3 a iscoaxially covered by a cylindrical outer tube 2 whose diameter is largerthan that of the inner tube 3 a. The inner tube 3 a and the outer tube 2are made of a translucent material such as quartz glass, and they areeach connected to discs side plates 15 a and 15 b by welding, therebyforming an integral structure. The side plates 15 a and 15 b are made oftranslucent material such as, for example, quartz glass.

A heat-insulating material (not shown in Figures) is disposed outsidethis outer tube 2, and the tube is covered by a plastic case (not shownin Figures) which is hardly deformed even at high temperatures, such asPP, PVC or PTFE. A space between the inner tube 3 a and the outer tube 2forms a passage for the sulfuric acid-based chemicals. An emission line5 such as a halogen lamp is inserted in the inside of the lamp heater 4,light emitted from the emission line 5 penetrates through the inner tube3 a, and the chemicals are exposed to the light and is heated.

In a peripheral wall of the outer tube 2, an inlet 7 and an outlet 8 forthe chemicals, located at the side of the side plate 15 a are provided,and the inlet 7 is disposed at a lower part and the outlet 8 is disposedat an upper part.

A colored material which is not corroded by the chemicals, such as anamorphous carbon pipe 1, is disposed in a space between the inner tube 3a and the outer tube 2, and this amorphous carbon pipe 1 is fixed byengagement of a first passage partition member 6 a, which is providedinside the outer tube 2 and on the side of the side plate 15 a, and asecond passage partition member 6 b, which is provided outside the innertube 3 a and or the side of the side plate 15 b. One or morethrough-holes 16 through which the chemicals passes are provided in thesecond passage partition member 6 b. Furthermore, the inlet 7 is locatedbetween the first passage partition member 6 a and the side plate 15 a,and the outlet 8 is located between the first passage partition member 6a and the side plate 15 b.

In this embodiment, the amorphous carbon pipe 1 is used as the coloredmaterial which is not corroded by the chemicals, but it is also possibleto use, for example, a pipe composed of colored quartz glass includingblack one, foam glass, SiC, Teflon® or polyimide. In such a case, adesign which considers the change in shape depending on the temperaturevariation is necessary since material data depend on the material beused varies, like the amorphous carbon pipe having a coefficient ofthermal expansion of 2 to 3.4×10⁻⁶/° C. and the quartz glass having acoefficient of thermal expansions of 5.5×10⁻⁷/° C.

The space between the inner tube 3 a and the outer tube 2, the amorphouscarbon pipe 1, and the first and the second passage partition members 6a and 6 b form the passage for the chemicals as shown by arrows.

This passage for the chemicals will be explained in detail.

The chemicals which enters from the inlet 7 located at the lower endside of the outer tube 2 passes through a space between the side plate15 a and the first passage partition member 6 a, and then passes througha space between the inner tube 3 a and the amorphous carbon pipe 1,followed by the through-hole 16 in the second passage partition member 6b, and reaches the side plate 15 b located on the other end side of theor tube 2. The solution turns back and flows in the opposite direction,passes through a apace between the outer tube 2 and the amorphous carbonpipe 1, and exits the outlet 8 located on the upper end side of theouter tube 2. By forming such a passage, the chemicals flow turbulently.

Next, a method for heating the chemicals will be explained.

Light emitted from the emission line 5 in the lamp heater 4 istransmitted through the inner tube 3 a, and the chemicals which passthrough the space between the inner tube 3 a and the amorphous carbonpipe 1 is irradiated with the transmitted light, whereby the chemicalsare radiation-heated. At this time, the amorphous carbon pipe 1 isirradiated with a part of the light transmitted through the chemicalswithout being utilized for the radiation-heating, whereby the amorphouscarbon pipe 1 is heated and the chemicals that are in contact withheated amorphous carbon pipe 1 are heated by the heat-conduction. Thatis, both of the chemicals which pass through the space between the outertube 2 and the amorphous carbon pipe 1, and the chemicals which passthrough the space between the inner tube 3 a and the amorphous carbonpipe 1 are heated by the heat-conduction from the amorphous carbon pipe1. The chemicals thus heated exit the outlet 8.

As stated above, according to the first embodiment of the presentinvention, the passage for the chemicals is formed by disposing theamorphous carbon pipe 1 between the inner tube 3 a and the outer tube 2.Therefore, the flow rate of the chemicals can be increased and the flowcan be made turbulent, and thus the convection-heating and theconduction-heating can be promoted. Particularly, when the sulfuricacid-based chemicals is used as the fluid, the heating efficiency can bemore improved by the fluid heating device of this embodiment whereinlight energy is absorbed in the amorphous carbon pipe 1 and convertedinto heat energy, and the chemicals are heated by conduction-heating,than by conventional fluid heating devices wherein 30% to 40% lightenergy is absorbed in the heat-insulating material disposed outside theouter tube 2. Therefore, even in the sulfuric acid-based chemicals thathave a low light absorption percent, the heating efficiency can bemaximized, the temperature increase of the case of the fluid heatingdevice can be suppressed, and the chemicals can also easily reach thedesired temperature.

Furthermore, the risk of leakage of the chemicals can be reduced byconnecting each of the inner tube 3 a and the outer tube 2 to the discside plates 15 a and 15 b by welding to thereby form an integralstructure.

FIG. 2 is a schematic view showing a longitudinal section of a fluidheating device according to a second embodiment of the presentinvention, in which the same reference numerals are given to the sameparts as in FIG. 1( a), and only differing parts will be explained. Itshould be noted that FIG. 2 is a longitudinal cross-sectional viewcorresponding to a-a′ line in FIG. 1( b).

A third passage partition member 6 c, which is disposed inside an outertube 2 and on the side of a side plate 15 a, is provided with a screwthread. Furthermore, a screw thread is formed at one end of an amorphouscarbon pipe 1, which is disposed in a space between an inner tube 3 aand the outer tube 2. The amorphous carbon pipe 1 is fixed between theinner tube 3 a and the outer tube 2 by screwing the one end of theamorphous carbon pipe 1 on the third passage partition member 6 c.

It should be noted that the screw threads formed on the third passagepartition member 6 c and the one end of the amorphous carbon pipe 1 maybe an internal thread type in which the amorphous carbon pipe 1 is fixedinside the member, or an external thread type in which the amorphouscarbon pipe 1 is fixed outside the member.

A stated above, in the second embodiment of the present invention, thesame effects as those obtained in the first embodiment can also beobtained.

FIG. 3( a) shows schematic views showing longitudinal cross-sections ofa fluid heating device according to a third embodiment of the presentinvention, in which FIG. 3( b) is a cross-sectional view correspondingto B-B′ line in FIG. 3( a), and FIG. 3( a) is a longitudinalcross-sectional view corresponding to b-b′ line in FIG. 3( b). It shouldbe noted that, in FIG. 3, the same reference numerals are given to thesame parts as in FIG. 1, and the explanation thereof will be omitted,

As shown in FIGS. 3( a) and (b), the fluid heating device has two innertubes 3 a, and a lamp heater 4 is inserted into each of the two innertubes 3 a. Amorphous carbon plates 10 a and 10 b, which are composed ofa colored material that is not corroded by chemicals, are disposedinside an outer tube 2 and on the upper and lower sides of the two innertubes 3 a.

A fixing member 12 is provided inside the side plate 15 a and inside theouter tube 2, and the lower amorphous carbon plate 10 b is fixed by thefixing member 12. Furthermore, a fixing member 12 is provided inside theside plate 15 b and inside the outer tube 2, and the upper amorphouscarbon plate 10 a disposed is fixed by the fixing member 12.

An inlet 7 for fluid is provided on a lower surrounding wall of theouter tube 2 located on the side of the side plate 15 a, and an outlet 8for fluid is provided on an upper surrounding all of the outer tube 2located on the side of the side plate 15 b.

As shown in FIG. 3( b), the amorphous carbon plates 10 a and 10 b aredisposed in parallel across the lamp heaters 4, and thus there are siteswhere light emitting from the lamp heater 4 reaches the outer tube 2without interruption of the amorphous carbon plates. Light reflectingplates 11 are provide on the sites, which are on the outer tube 2 and onthe outsides of the side plates 15 a and 15 b. Due to this structure,light emitting from the lamp heater 4 is reflected by the lightreflecting plates 11, and the reflected light is absorbed in theamorphous carbon plates 10 a and 10 b and converted into heat energy.

The space between the inner tube 3 a and the outer tube 2, and theamorphous carbon plates 10 a and 10 b forms a passage for the chemicalsas shown by arrows in FIG. 3( a).

This passage for the chemicals will be explained in detail.

The chemicals which enters from the inlet 7 located on the lower endside of the outer tube 2 passes through a space between the outer tube 2and the lower amorphous carbon plate 10 b, and reaches the side plate 15b located on the opposite end side of the outer tube 2. The solutionturns backs and flows in the opposite direction, passes through a spacebetween the lower amorphous carbon plate 10 b and the upper amorphouscarbon plate 10 a, and teaches the side plate 15 a located on the oneend side of the outer tube 2. The solution turns back and flows in theopposite direction, passes through a space between the outer tube 2 andthe upper amorphous carbon plate 10 a, and exits the outlet 8 located onthe upper end side of the outer tube 2. When such a passage is formed,the chemicals flow turbulently.

Next, a method for heating the chemicals will be explained.

Light emitted from the emission line 5 in the lamp heater 4 istransmitted through the inner tubes 3 b, and the chemicals which passthrough the space between the upper amorphous carbon date plate 10 a andthe lower amorphous carbon plate 10 b, whereby the chemicals areradiation-heated. At this time, the amorphous carbon plates 10 a and 10b are irradiated with a part of the light which is transmitted throughthe chemicals without being utilized for the radiation-heating, and thereflected light which is reflected by the light reflecting plates 11 isabsorbed in the amorphous carbon plates 10 a and 10 b. This heats theamorphous carbon plates 10 a and 10 b, and the chemicals which arebrought into cons act with the heated amorphous carbon plates 10 a and10 b are heated by the heat-conduct ion. That is, both of the chemicalswhich pass through the space between the outer tube 2 and each of theamorphous carbon plates 10 a and 10 b, and chemicals which pass throughthe space between the upper amorphous carbon plate 10 a and the loweramorphous carbon plate 10 b, are heated by the heat-conduction from theamorphous carbon plates 10 a and 10 b. The chemicals thus heated exitthe outlet 8.

As stated above, in the third embodiment of the present invention, thesame effects as those obtained in the first embodiment can also beobtained. In addition, when the amorphous carbon plates 10 a and 10 b,and the light reflecting plates 11 are provided, the light emitted fromthe lamp heater 4 is reflected by the light reflecting plates 11, andthe reflected light is converted into heat energy by the amorphouscarbon plates 10 a and 10 b. This enables the fluid to be heated by theconvection and the heat-conduction, in addition of the radiation-heatingby the lamp heater 4.

FIG. 4( a) is schematic views showing longitudinal sections of a fluidheating device according to a fourth embodiment of the presentinvention, in which FIG. 4( b) is a cross-sectional view correspondingto D-D′ line in FIG. 4( a), and FIG. 4( a) is a longitudinal sectionview corresponding to d-d′ line in FIG. 4( b). It should be noted that,in FIG. 4, the same numerals are given to the same parts as in FIG. 1,and the explanation thereof will be omitted.

As shown in FIGS. 4( a) and (b), the fluid heating device has threeinner tubes 3 b, 3 c and 3 d, and a lamp heater 4 is inserted into eachof the inner tubes 3 b, 3 c and 3 d. Amorphous carbon plates 10 c, 10 dand 10 e are disposed, which separate the inner tubes 3 b, 3 c and 3 dfrom each another, in an outer tube 2. Each of the amorphous carbonplates 10 c, 10 d and 10 e is fixed by fixing member 12 which isprovided inside the outer tube 2, fixing members which are provided onside plates 15 a and 15 b, respectively, and a central axis member 12 awhich is disposed on the central axis of the outer tube 2.

Particularly, as shown in FIG. 4( a), the amorphous carbon plate 10 e,which is located on the lower side in the view, is fixed to the sideplate 15 a and the inside of the outer tube 2; the amorphous carbonplate 10 c which is located on the upper side in the view is fixed tothe side plate 15 b and the inside of the outer tube 2; and theamorphous carbon plate 10 d reach is located at the center in the viewis fixed to the side plates 15 a and 15 b, and the inside of the outertube 2 across from the side plate 15 a to the side plate 15 b.

An inlet 7 for fluid is provided on a lower surrounding wall of theouter tube 2 which is located on the side of the side plate 15 a, and anoutlet 8 for fluid is provided on an upper surrounding wall of the outertube 2 which is located on the side of the side plate 15 b.

In addition, as shown in FIG. 4( b), there are sites where lightemitting from the lamp heater 4 reaches the outer tube 2 withoutinterruption of the amorphous carbon plates 10 c, 10 d and 10 e. Lightreflecting plates 11 are provided on the sites, which are on the outertube 2 and outside the side plates 15 a and 15 b. Due to this structure,light emitting from the lamp heater 4 is reflected by the lightreflecting plates 11, and the reflected light is absorbed in theamorphous carbon plates 10 c, 10 d and 10 e and converted into heatenergy.

The space between inner tube 3 a and the outer tube 2, and the amorphouscarbon plates 10 a, 10 d and 10 e forms a passage for the chemicals asshown by arrows in FIG. 4( a).

This passage for the chemicals will be explained in detail.

The chemicals which enters from the inlet 7 located on the lower endside of the outer tube 2 passes through a space formed by the outer tube2 and the amorphous carbon plates 10 d and 10 e, and reaches the sideplate 15 b located on the opposite end side of the outer tube 2. Thesolution turns back and flows in the opposite direction, passes througha space formed by the outer tube 2 and the amorphous carbon plates 10 cand 10 e, and reaches the side plate 15 a located on the one end side ofthe outer tube 2. The solution turns back and flows in the oppositedirection, passes through a apace formed by the outer tube 2 and theamorphous carbon plates 10 c and 10 d, and exits the outlet 8 located onthe upper end side of the outer tube 2. When such a passage is formed,the chemicals flow turbulently.

Next, a method for heating the chemicals will be explained.

Light emitted from the emission line 5 in the lamp heater 4 istransmitted through the inner tubes 3 b, 3 c and 3 d, and the chemicalswhich pass through the inside of the tube 2 is irradiated with thetransmitted light, whereby the chemicals are radiation-heated. At thistime, the amorphous carbon plates 10 c, 10 a and 10 b are irradiatedwith a part of the light which is transmitted through the chemicalswithout being utilized for the radiation-heating, and the reflectedlight which is reflected by the light reflecting plates 11 is absorbedin the amorphous carbon plates 10 c, 10 d and 10 e. This heats theamorphous carbon plates 10 c, 10 d and 10 e, and the chemicals which arebrought into contact with the heated amorphous carbon plates 10 c, 10 dand 10 e is heated by the heat-conduction. The chemicals thus heatedexits the outlet 8.

As stated above, in the fourth embodiment of the present invention, thesame effects as those obtained in the first embodiment can also beobtained.

FIG. 5 is a schematic view showing a cross section of a fluid heatingdevice according to a fifth embodiment of the present invention, inwhich the same numerals are given to the same parts as in FIG. 1( b),and only differing parts will be explained.

Three inner tubes 3 b to 3 d are disposed in an amorphous carbon pipe 1in an outer tube 2, and a lamp heater is inserted into each of theseinner tubes 3 b to 3 d.

A passage for chemicals will be explained in detail.

The chemicals which enter from an inlet 7 located on a lower end side ofthe outer tube 2 pass through a space between a side plate and a firstpassage partition member, then a space between the inner tubes 3 b to 3d and at amorphous carbon pipe 1, followed by through-holes in a secondpassage partition member, and reach a side plate located on the oppositeend side of the outer tube 2. The solution turns back and flows in theopposite direction, passes through a space between the outer tube 2 andthe amorphous carbon pipe 1, and exits an outlet 8 located on an upperend side of the outer tube 2. When such a passage is formed, thechemicals flow turbulently.

In the fifth embodiment, the same effects as those obtained in the firstembodiment can also be obtained.

FIG. 6 is a schematic view showing a cross section of a fluid heatingdevice according to a sixth embodiment of the present invention, inwhich the same numerals are given to the same parts as in FIG. 4( b),and the explanation thereof will be omitted.

The two devices are different from each other in that in the fluidheating device shown in FIG. 4( b), the three inner tubes 3 b to 3 d aredisposed inside the outer tube 2, but in the fluid heating device shownin FIG. 6, four inner tubes 3 b to 3 e are disposed inside of the outertube 2. With the setting up of the four inner tubes 3 b to 3 e, apassage for the chemicals is formed by four amorphous carbon plates 10 cto 10 f.

The passage for the chemicals will be explained in detail.

The chemicals which enter from an inlet 7 located on a lower end side ofthe outer tube 2 passes through a space formed by the outer tube 2 andamorphous carbon plates 10 f and 10 e, and reaches a side plate 15 blocated on the opposite end side of the outer tube 2. The solution turnsback and flows in the opposite direction, passes through a space formedby the outer tube 2 and the amorphous carbon plates 10 e and 10 d, and aspace formed by the outer tube 2 and amorphous carbon plates 10 f and 10c, and reaches the outer tube 2. The solution turns back and flows inthe opposite direction, passes through a space formed by the outer tube2 and the amorphous carbon plates 10 d and 10 c, reaches a side plate 15b located on the opposite end side of the outer tube 2, and exits anoutlet 8 located on an upper end side of the outer tube 2. When such apassage is formed, the chemicals flow turbulently.

In the sixth embodiment, the same effects as those obtained in thefourth embodiment can also be obtained.

FIG. 7 is a schematic view showing a cross section of a fluid heatingdevice according to a seventh embodiment of the present invention, inwhich the same reference numerals are given to the same parts as in FIG.3( b), and only differing parts will be explained.

The both devices are different from each other in that in the fluidheating device shown in FIG. 3( b), the two inner tubes 3 a are disposedinside of the outer tube 2, but in a fluid heating device shown in FIG.7, four inner tubes 3 b to 3 e are disposed inside an outer tube 2. Withthe setting-up of the four inner tubes 3 b to 3 e, a passage for thechemicals is formed by three amorphous carbon plates 10 a to 10 c.

This passage for the chemicals will be explained in detail.

The chemicals which enter from an inlet 7 located on a lower end side ofthe outer tube 2 passes through a space between the outer tube 2 and alower amorphous carbon plate 10 c, and reaches a side plate 15 b locatedon the opposite end side of the outer tube 2. The solution turns backand flows in the opposite direction, passes through a space between thelower amorphous carbon plate 10 c and a central amorphous carbon plate10 b, and reaches a side plate 15 a located on one end side of the outertube 2. Then, the solution turns back and flows in the oppositedirection again, passes through a space between the central amorphouscarbon plate 10 b and an upper amorphous carbon plate 10 a, and reachesa side plate 15 b located on the opposite end side of the outer tube 2.Then, the solution turns back and flows in the opposite direction,passes through a space between the outer tube 2 and the upper amorphouscarbon plate 10 a, and exits an outlet 8 located on an upper end side ofthe outer tube 2. By forming such a passage, the chemicals flowturbulently.

In the seventh embodiment, the same effects as those obtained in thethird embodiment can also be obtained.

FIG. 8 is a schematic view showing a cross section of a fluid heatingdevice according to an eighth embodiment of the present invention, inwhich the same reference numerals are given to the same parts as in FIG.1( b), and only differing parts will be explained.

Four inner tubes 3 b to 3 e are disposed inside an amorphous carbon pipe1 in an outer tube 2. A lamp heater is inserted into each of these innertubes 3 b to 3 e.

A passage for chemicals will be explained in detail.

The chemicals which enter from an inlet 7 located on a lower end side ofthe outer tube 2 passes through a space between a side plate and a firstpassage partition member, then a space between inner tubes 3 b to 3 eand an amorphous carbon pipe 1, followed by through-holes in a secondpassage partition member, and reaches a side plate located on theopposite end side of the outer tube 2. Then, the solution turns back andflows in the opposite direction, passes through a space between hoeouter tube 2 and the amorphous carbon pipe 1 and exits an outlet 8located on an upper end side of the outer tube 2. By forming such apassage, the chemicals flow turbulently.

In the eighth embodiment, the same effects as those obtained in thefirst embodiment can also be obtained.

The present invent ion is not limited to the embodiments describedabove, and various modifications can be carried out within the range notdeparting from the inventive concepts

EXPLANATION OF REFERENCE NUMERALS

-   1: amorphous carbon pipe-   2: outer tube-   3 a, 3 b, 3 c, 3 d and 3 e: inner tubes-   4: lamp heater-   5: emission line-   6 a: first passage partition member-   6 b: second passage partition member-   6 c: third passage partition member-   7: fluid inlet-   8: fluid outlet-   10 a, 10 b, 10 c, 10 d, 10 e and 10 f: amorphous carbon plates-   11: light reflecting plate-   12: fixing member-   15 a and 15 b: side plates-   16: through-hole

1. A fluid heating device for heating sulfuric acid-based chemicals,comprising: a translucent inner tube; a lamp heater disposed in theinner tube; a translucent outer tube disposed outside the inner tube;translucent side plates disposed on both sides of the outer tube; alight-absorbing material disposed between the outer tube and the innertube; and a light reflecting plate disposed on the outer tube and on theoutsides of the side plates, wherein the light-absorbing material isdisposed so as to be in contact with chemicals passing through a spacebetween the outer tube and the inner tube, and wherein thelight-absorbing material includes amorphous carbon, colored quartz glassor SiC.
 2. The fluid heating device according to claim 1, wherein eachof the inner tube, the outer tube and the side plate includes quartz,the inner tube and the outer tube are connected to the side plates,respectively, by welding and they are integrally formed.
 3. The fluidheating device according to claim 1, wherein the light-absorbingmaterial forms a passage for the chemicals passing through a spacebetween the outer tube and the inner tube.
 4. The fluid heating deviceaccording to claim 2, wherein the light-absorbing material forms apassage for the chemicals passing through a space between the outer tubeand the inner tube.